I've got an odd problem with my home office network. When one particular desktop computer shutsdown the entire network seems to die.

The network consists of a Netgear WNDR4000 wireless router attached to a Motorola broadband cable modem. There is a Netgear GS108T switch and a Netgear GS108 switch. There are a number of wired and wireless devices connected to the network, including a ReadyNAS Ultra 6.

The problem has only started after I replaced a faulty GS108T switch. The network was working fine with the previous GS108T switch and all other devices. It was also working ok when the GS108T switch was out of the network while waiting for a replacement. The replacement GS108T is a version 2, while the original one was a version 1.

The computer that seems to cause the problem has 2 wired LAN connections. One to the GS108T and another to the WNDR4000. I have jumbo frames enabled on the LAN connection to the GS108T but not to the WNDR4000 (it doesn't support jumbo frames).

The GS108T is connected to the GS108 plus other computers and with one LAN connection to the Ultra 6. The WNDR4000 is connected to a network printer (a Xerox DocuPrint C2535A), the Ultra 6 and one other computer.

When the computer in question is shutdown the entire network (both wired and wireless) seems to die. I can't access either local devices or access the Internet from anything when the one computer is off. Some devices will lock up and need to be rebooted once the computer is on again and the network is working. (Specifically a Logitech Squeezebox Touch.)

Any ideas of what might be causing this problem and how to get the network to work correctly without having to leave one computer running constantly? Could there be some setting in the replacement GS108T that's causing this? Could there be some conflicting setting between the GS108T and the one computer? Any ideas greatly appreciated.

Thanks.